2026

.NET Core Interview Questions 2026

A current, 2026 snapshot of the .NET Core interview questions worth knowing — kept up to date as frameworks and best practices evolve, so you prepare with what companies are actually asking in 2026.

109Questions15Beginner14Intermediate80Senior

109 .NET Core questions

  1. 1What are minimal APIs in .NET Core?Intermediate
  2. 2What is authentication vs authorization?Intermediate
  3. 3What is IHttpClientFactory?Intermediate
  4. 4What are filters in ASP.NET Core?Intermediate
  5. 5What is caching in .NET Core?Intermediate
  6. 6What is model validation in ASP.NET Core?Intermediate
  7. 7What is logging in .NET Core?Intermediate
  8. 8Explain configuration providers in .NET CoreIntermediate
  9. 9What is asynchronous programming in .NET Core and why is it important?Intermediate
  10. 10Explain Dependency Injection lifetimes in .NET CoreIntermediate
  11. 11What is Entity Framework Core?Beginner
  12. 12What is IActionResult?Beginner
  13. 13What is model binding?Beginner
  14. 14What is routing in ASP.NET Core?Beginner
  15. 15What is Kestrel server?Beginner
  16. 16What is appsettings.json?Beginner
  17. 17What is Dependency Injection in .NET Core?Beginner
  18. 18What is middleware in ASP.NET Core?Beginner
  19. 19What is Program.cs in .NET Core?Beginner
  20. 20What is .NET Core and how is it different from .NET Framework?Beginner
  21. 21What is .NET Core and how is it different from .NET Framework?Beginner
  22. 22What is Dependency Injection in .NET Core?Intermediate
  23. 23How does configuration work in .NET Core?Intermediate
  24. 24What is routing in .NET Core?Beginner
  25. 25What is middleware in .NET Core?Senior
  26. 26How would you design a self-healing system in .NET Core?Senior
  27. 27How would you implement circuit breaker at system level in .NET Core?Senior
  28. 28How does .NET Core optimize serialization for high-performance scenarios?Senior
  29. 29How would you design a pluggable modular architecture in .NET Core?Senior
  30. 30How does .NET Core support advanced API throttling and quota management?Senior
  31. 31How would you implement a distributed locking mechanism in .NET Core?Senior
  32. 32How does .NET Core handle high-frequency real-time data ingestion?Senior
  33. 33How would you design a CQRS + Event Sourcing system in .NET Core?Senior
  34. 34How does .NET Core support advanced request batching and aggregation?Senior
  35. 35How would you design a distributed caching invalidation strategy across multiple regions in .NET Core?Senior
  36. 36How do you implement advanced authorization strategies in .NET Core?Senior
  37. 37How would you optimize cold start in serverless .NET Core apps?Senior
  38. 38How does .NET Core handle load balancing strategies?Senior
  39. 39How do you design a resilient message processing system in .NET Core?Senior
  40. 40How would you implement feature flags in .NET Core applications?Senior
  41. 41How does .NET Core support high-performance networking?Senior
  42. 42How would you design a rate-limited API gateway in .NET Core?Senior
  43. 43How does .NET Core handle large file uploads efficiently?Senior
  44. 44How do you implement idempotency in .NET Core APIs?Senior
  45. 45How would you design a globally distributed, eventually consistent system in .NET Core?Senior
  46. 46How do you design a real-time data processing system using .NET Core?Senior
  47. 47How would you design a resilient retry mechanism in .NET Core?Senior
  48. 48Explain advanced logging strategies for large-scale .NET Core systemsSenior
  49. 49How does .NET Core support horizontal scaling in cloud environments?Senior
  50. 50How would you secure secrets and sensitive data in .NET Core applications?Senior
  51. 51How do you implement advanced caching strategies like cache invalidation in .NET Core?Senior
  52. 52How does .NET Core optimize startup time and cold start performance?Senior
  53. 53How do you implement high-performance streaming APIs in .NET Core?Senior
  54. 54How does .NET Core handle distributed transactions and consistency?Senior
  55. 55How would you design a multi-tenant SaaS architecture in .NET Core at scale?Senior
  56. 56How do you design multi-region deployments in .NET Core?Senior
  57. 57How do you optimize database access in .NET Core for large systems?Senior
  58. 58How does .NET Core handle high availability in distributed systems?Senior
  59. 59How do you implement observability in .NET Core applications?Senior
  60. 60Explain zero-downtime deployment strategies in .NET CoreSenior
  61. 61How does .NET Core support event-driven architecture?Senior
  62. 62How would you design fault-tolerant distributed systems in .NET Core?Senior
  63. 63Explain backpressure handling in .NET Core systemsSenior
  64. 64How does .NET Core optimize garbage collection for large-scale applications?Senior
  65. 65How do you design a high-throughput, low-latency API in .NET Core for millions of users?Senior
  66. 66How does .NET Core handle graceful shutdown?Senior
  67. 67How does .NET Core support multi-tenancy?Senior
  68. 68What is the difference between IOptions, IOptionsSnapshot, and IOptionsMonitor?Senior
  69. 69How does .NET Core handle configuration reload at runtime?Senior
  70. 70What is the difference between synchronous and asynchronous I/O in .NET Core?Senior
  71. 71How does .NET Core implement distributed tracing?Senior
  72. 72Explain the role of Span<T> and Memory<T> in .NET CoreSenior
  73. 73How does .NET Core handle thread safety in high concurrency scenarios?Senior
  74. 74What are Channels in .NET Core and when should you use them?Senior
  75. 75How does .NET Core implement request pipeline performance optimizations internally?Senior
  76. 76What is clean architecture in .NET Core?Senior
  77. 77What is Dapper vs EF Core?Senior
  78. 78What is MediatR in .NET Core?Senior
  79. 79What is CQRS pattern in .NET Core?Senior
  80. 80How does .NET Core handle thread pool?Senior
  81. 81What is connection pooling in .NET Core?Senior
  82. 82What is EF Core tracking vs no-tracking queries?Senior
  83. 83How does .NET Core support OpenAPI/Swagger?Senior
  84. 84What is minimal hosting model in .NET Core?Senior
  85. 85How does .NET Core handle serialization?Senior
  86. 86What is Polly in .NET Core?Senior
  87. 87What is SignalR in .NET Core?Senior
  88. 88How does .NET Core support gRPC?Senior
  89. 89What is API versioning in .NET Core?Senior
  90. 90How do you implement rate limiting in .NET Core?Senior
  91. 91What is the difference between IHostedService and BackgroundService?Senior
  92. 92How does .NET Core handle exception handling globally?Senior
  93. 93What is background service in .NET Core?Senior
  94. 94How does .NET Core support containerization?Senior
  95. 95Explain health checks in .NET CoreSenior
  96. 96What is the role of IConfiguration in .NET Core?Senior
  97. 97How do you implement security best practices in .NET Core?Senior
  98. 98Explain caching strategies in .NET CoreSenior
  99. 99How does .NET Core support high performance APIs?Senior
  100. 100Explain middleware pipeline execution in depthSenior
  101. 101How does .NET Core handle memory management?Senior
  102. 102How do you design scalable microservices in .NET Core?Senior
  103. 103What is CommandType in ADO.NET and why is it important?Intermediate
  104. 104What is ExecuteScalar in ADO.NET and when should you use it?Beginner
  105. 105How does .NET Core support microservices architecture?Beginner
  106. 106What caching strategies are used in .NET Core?Senior
  107. 107How do you implement API versioning in .NET Core?Senior
  108. 108Why is async/await important in .NET Core?Beginner
  109. 109How does logging work in .NET Core?Intermediate

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Are these .NET Core interview questions up to date for 2026?

Yes. This page reflects 109 .NET Core interview questions kept current with today's frameworks, tooling and interview trends, with each answer maintained and dated.

What .NET Core topics should I focus on in 2026?

Prioritise the fundamentals plus the modern patterns interviewers ask about now. Each question here includes a detailed answer, code example and common mistakes so you can target the highest-impact areas.

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